1. Field of the Invention
The instant invention relates to a self-engaging tertiary safety for guns of the Colt Model 1911 Auto variety or similar design.
2. Description of Related Art
The Colt Model 1911 Auto is a well known handgun. The basic design was introduced by Colt in 1911 and adopted by Army Ordinance. The gun now comes in a variety of chamberings incorporating the basic design in a variety of frame size ranges. All varieties of the basic design operate in essentially the same way.
All past and present models of the gun have a variety of safety systems. First, a manual safety is located on the left rear side of the frame just below the slide. This manual safety is sometimes called the thumb lock safety and is often called the thumb safety. When the hammer is fully cocked and the thumb lock safety is applied, the upper part of the thumb lock safety engages a thumb safety notch in the slide. Simultaneously, an internal sear blocking stud on the thumb safety moves between the sear and the hammer body to prevent the hammer from moving forward when the trigger is squeezed. The thumb safety can be applied only when the slide is fully forward and the hammer is fully cocked.
The grip safety is an additional safety system that permits firing the handgun only when the grip safety is fully depressed by the web of the hand. The grip safety is located on the upper rear part of the receiver grip. The grip safety pivots around the thumb lock pivot shaft and makes contact at its lower end with a main spring housing and a sear spring. This configuration allows the grip safety to move relative to the main spring housing when the grip safety is depressed by the web of the hand when the pistol grip is grasped. The sear spring pushes the grip safety back to its original position thereby activating the grip safety when the web of the hand is removed from contact with the grip safety. An integral tang of the grip safety, sometimes called the stop tip, which is located inside the pistol frame, contacts the rear of the trigger to prevent its rearward movement. When the pistol grip is grasped, thereby depressing the grip safety, the grip safety stop tip is rotated out of contact with the rear of the trigger to allow the trigger to move.
The thumb and grip safeties may of course be inactivated by deliberate action. Unfortunately, however, these safeties may be inactivated inadvertently. In addition, the thumb and grip safetys may be inactivated in any order, that is, the thumb safety may be inactivated and then the grip safety inactivated by grasping the handle, or the grip safety may first be inactivated by grasping the handle and then the thumb safety deactivated. Because the safetys may be deactivated in any order, a problem is presented, particularly when the handgun is removed from a holster or similar confinement. In removing the handgun from the holster, the thumb safety may be inadvertently moved from an original activated position to a deactivated position by physical contact with objects near the holster or by friction with the holster as the handgun is pulled from the holster. Thereafter, as the handle of the gun is gripped, the grip safety is deactivated. Because both safeties are now deactivated, contact with the trigger may fire the pistol despite the user's belief that the thumb safety is still engaged. The proceeding sequence of events may occur without the gun user being aware that the thumb safety has been deactivated. This is particularly dangerous where the gun user is unaware that the thumb safety has been deactivated and is acting in the mistaken belief that the thumb safety is still activated. This problem of the thumb safety being accidentally deactivated is a problem in want of a solution.